Carboxylic acid amide and hydrazide derivatives of 4,5-diphenyloxazole and process for preparing them

ABSTRACT

Pharmacologically active carboxylic acid amide and hydrazide derivatives of 4,5-diphenyloxazole of the general formula:   D R A W I N G

United States Patent 1 Marchetti [45] Dec. 9, 1975 [5 CARBOXYLIC ACID AMIDE AND [56] References Cited "YDRAZIDE DERIVATTVES OF UNITED STATES PATENTS 4S'DIPHENYLOXAZOLE AND PROCESS 3.51am: 5/1971 Brown 260/307 FOR PREPARING THEM Enzo Marchetti, Rome, Italy Institute Farmacologico Serono S.p.A., Rome, Italy Filed: Apr. 23, 1973 Appl. No.: 353,675

Related US. Application Data Division of Ser. No. 119,832, March I. 1971, Pat No. 3,869,455.

Inventor:

Assignee:

Foreign Application Priority Data Mar. 5, [970 Italy r. 21550/70 U.S. CL... 260/307 R; 260/247 SE; 260/471 A;

260/570 R; 424/248; 424/272 Int. Cl. C07D 263/38 Field of Search 260/307 R, 247.2 A

OTHER PUBLlCATlONS Marchett CA. 75, l5l776g (l97l) Abstract of Ger. Offen. 2,110,363.

Primary Examiner-Raymond V. Rush Attorney, Agent, or Firm-Dennis P. Clarke {57] ABSTRACT Pharmacologically active carboxylic acid amide and hydrazide derivatives of 4,5-diphenyloxazole of the general formula:

0 ll II II 6 Claims, No Drawings CARBOXYLIC ACID AMIDE AND HYDRAZIDE DERIVATIVES OF 4,5-DIPIIENYLOXAZOLE AND PROCESS FOR PREPARING THEM This is a division, of application Ser. No. 119832, filed Mar. l, 1971. This invention relates to a series of Carboxylic acid amide and hydrazide derivatives of 4,5-diphenyloxazole of the general formula:

2 cants Italian Patent Application No l2243 A/68 filed Jan. 31, I968.

In accordance with this invention, the compounds of the general formula (I) are prepared through aminolysis or hydrazinolysis of an ester of the general formula wherein I1 is 0, l or 2 and R represents an alkyl radical having I to 4 carbon atoms, by using an amine or hydrazine of the general formula (VI):

H-R (Vll wherein R is as defined above. The above ester (V) can be prepared in turn by acylating a-phenyl-aaminoacetophenone (II) with a dicarboxylic acid monoester-monochloride of the general formula (III) and thereafter cyclizing the resulting acylamino-derivative (IV) with phosphorus oxychloride or similar condensing agents in accordance with the following scheme:

C,H -,-1HNH, C.H,-,- 0 ClCO(CH,),,-CO0R' (II) (III) C,H iI-INHCO(CH,),,-COOR' C.,H,,-|:| 1fi POCI C.H,- 0 C,,H,, C C(CH,),,-COOR +H-R v!) c.H, fifl C,H .,-C\ /C CH, ,,-COR

include: In the above scheme n, R and R are as defined above.

The acylation of a-amino-a-phenyl-acetophenone (II) with the monoester-monochloride (III) is suitably NBC"? "(92%) 2 N I d "H4452. carried out on the hydrochloride of (II) in an inert solvent such as benzene or toluene at the boiling point of the mixture, the molar ratio of the reagents being pref- NH-MCH 3 2 erably of about 1:1.

The compounds of the general formula (I) are charactcrized by a marked analgesic activity often together with an antiphlogistic activity and a depressing action on the central nervous system.

4,5-diphenyl-substituted oxazole derivatives bearing a secondary or tertiary amino group (Applicant's Italian Patent Application No. 18390/66 (37/499) filed Aug. 10, I966) or a carboxyl group in the 2-position of the ring, which is one or more methylene groups away from the heterocyclic ring, are known to have antiphlogistic, analgesic and antiulcerogenic properties (Nature 219,164, I968).

In addition, the N-amidino-carbonamides of the same acids are also known to enhance the diuretic and natruretic activities of benzothiazidine type diuretics (Appli The acylamino compound (IV) is then cyclized to the oxazole derivative (V) with POCI JCI or the like in inert solvents such as benzene or toluene, at temperatures ranging from room temperature to the boiling point of the mixture. The reaction of the ester (V) with the appropriate base (VI) is carried out in the presence or in the absence of a suitable organic solvent (benzene, toluene, xylene and so on) depending on the specific reactivities of the reagents, at temperatures of from 20 to I20C and for reaction times ranging from 1 to 36 hours.

A modification of the above procedure, which modification can be applied only to the compounds of the formula (I) wherein n is l or 2, comprises hydrolizing with an alkali a corresponding ester (V) wherein n is 1 or 2 to give a corresponding caroxylic acid which is then converted to the acid chloride by using thionyl EXAMPLE I 4,5-Diphenyl-Z-oxazolyl-carboxylic acid N ,N -diethylamide A solution of 8.8 g. 2-carbethoxy-4,S-diphenyloxazole (prepared according to Chemical Abstracts 58, 3408) in 31 ml. diethylamine was refluxed for 24 hours. The excess diethylamine was removed at 20 mm. pres sure, the residue was dissolved in 100 ml. of boiling 70% ethanol and, upon cooling the solution, 7 g. of 4,5- diphenyl-2-oxazolyl-caroxylic acid N,N-diehtylamide crystallized, m.p. l30l32C (yield 73%).

EXAMPLE 2 4,5-Diphenyl-2-oxazolyl-carboxylic acid N ,N '-dimethylhydrazide A mixture of 11.6 g. 2-carbethoxy-4,S-diphenyloxazole (prepared as indicated in Example 1) and 18 g. N,N-dimethylhydrazine was refluxed for 4 hours on a boiling water bath. The excess N,N-dimethylhydrazine was removed at 20 mm. pressure, the residue was dissolved in I50 ml. of boiling 95% ethanol and, upon cooling to C 9 g. of 4,5-diphenyl-2-oxazolyl-carboxylic acid N',N'-dimethylhydrazide crystallized, m.p. l90-l92C (yield 73%).

EXAMPLE 3 a. a-Phenyl-a-(N-carbethoxyacetylamino)acetophenone A mixture of 6.2 g. a-phenyl-a-amino-acetophenone hydrochloride and 5.2 g. carbethoxy-acetylchloride in 40 ml. anhydrous benzene was refluxed for 4 hours. The boiling mixture was filtered, the filtrate was cooled to l5C and diluted with 20 ml. ligroin (boiling range 30 to 60C). Upon cooling to 0C, 6.5 g. a-phenyl-a- (N-carbethoxyacetylamino)-acetophenone crystallized, m.p. 9092C (yield 80%).

b. Ethyl 4,5-diphenyl-2-oxazolylacetate A solution of 6.5 g. a-phenyl-a-(N-carbethoxyacetylamino )-acetophenone and 8 g. phosphorus oxychloride in ml. anhydrous benzene was refluxed for 1 hours. The solvent was removed at mm. pressure and the oily residue was taken up with 60 ml. 50% ethanol, whereby 4.9 g. crystalline ethyl 4,5-diphenyl-2- oxazolylacetate gradually separated, m.p. 65-67C (yield 79%).

c. 4,5-Diphenyl-Z-oxazolylacetic acid N-methylamide A mixture of 9 g. ethyl 4,S-diphenyl-2-oxazolylacetate and 100 ml. of a 20% benzene solution of methylamine was kept in a stoppered flask for 36 hours at 22C. Upon diluting the benzene solution with 100 ml. ligroin, 7.2 g. 4,5-diphenyl-2-oxazolylacetic acid N- methylamide crystallized, m.p. 81%).

l39 l 42C (yield EXAMPLE 4 4,5-Diphenyl-2-oxazolylacetic acid morpholide 6 g. ethyl 4,5-diphenyl-2-oxazolylacetete (prepared as described in Example 3 a-b) and 17 g-morpholine were refluxed for 6 hrs. The excess morpholine was re moved at 20 mm. pressure and the oily residue was taken up with 100 ml. 50% ethanol, whereby the crystalline 4,5-diphenyl-2-oxazolylacetic acid morpholide gradually separated. The recrystallization of this compound from a mixture of absolute ethanolanhydrous ether-ligroin gave 4.2 g. of a product melting at l27l29C (yield 60 EXAMPLE 5 4,5-Diphenyl-2-oxazolylacetic acid hydrazide A solution of 6 g. ethyl 4,5-diphenyl-2-oxazolylacetate (prepared as described in Example 3 a-b) in 50 ml. absolute ethanol was treatet with lo ml. 98 hydrazine hydrate. The reaction mixture was maintained at 22C for 1 hr., after which 50 ml. distilled water were added to completely precipitate the 4,5-diphenyl-2- oxazolylacetic acid hydrazide which was then purified by crystallization from ethanol to give 4,7 g. of a product melting at l64-l65C (yield 79 EXAMPLE 6 a. a-Phenyl-a-[N-(B-carbomethoxypropionyl)-amino]- acetophenone- A mixture of 7.4 g. a-phenyl-a-aminoacetophenone hydrochloride and 6 g. B-carbomethoxypropionyl chloride in 60 ml. anhydrous benzene was refluxed for 5 Hrs. After filtering the boiling mixture and cooling the filtrate to 15C, 20 ml. ligroin (boiling 30 to 60C) were added. Upon cooling to 0C, 8.5 g. a-phenyl-a- [N-(B-carbomethoxypropionyl)-amino]-acetophenone crystallized, m.p. l03-l04C (yield 87 b. Methyl 3-(4,5-diphenyl-2-oxazolyl)-propionate A solution of 6.5 g. a-phenyl-a-lN-(fl-carbomethoxypropionyl-amino]-acetophenone and 8 g. phosphorus oxychloride in 20 ml. anhydrous benzene was refluxed for l hr. The solvent was removed at 20 mm. pressure and the oily residue was taken up with 60 ml. 50 ethanol. From the resulting solution at room temperature 5.2 g. methyl 3-(4,S-diphenyl-Z-oxazolyl)-propionate crystallized, m.p. 58-59C (yield c. 3-(4,5-diphenyl-2-oxazolyl)-propionic acid pyrrolidide 9.2 g. methyl 3-(4,5-diphenyl-2-oxazolyl)-propionate and 25 ml. pyrrolidine were refluxed for 3 hours. The excess pyrrolidine was removed at 20 mm. pressure and the oily residue was taken up with ml. 70% ethanol. Upon cooling to 0C, 8.5 g. 3-(4,5-diphenyl-2- oxazolyl)-propionic acid pyrrolidide crystallized from the resulting solution; m.p. 62-66C (yield 82%).

EXAMPLE 7 a. 3-(4,S-diphenyl-Z-oxazolyl)-propionic acid 6.1 g. methyl 3-(4,5-diphenyl-2-oxazolyl)-propionate (prepared as described in Example 6 a-b) were dissolved in a solution of 4 g. sodium hydroxide in 40 ml.

b. 3-(4,5-diphenyl-2-oxazolyl)-propionic acid N,N-diethylamide 12 g. 3-(4,5-diphenyl-2-oxazolyl)-propionic acid were suspenden into 100 ml. anhydrous benzene and '8.6 ml. thionyl chloride were added. The reaction mixture was amintained at room temperature for 1 hour, after which the excess solvent and thionyl chloride were removed at 5 mm. pressure. The oily residue was dissolved in 50 ml. anhydrous benzene and the resulting solution was added dropwise, under stirring, to a solution of 6 g. diehtylamine in 100 ml. anhydrous benzene, which had been previously cooled to 0C. After the completion of the addition the temperature was increased to 2225C, the reaction mixture was washed with water and the separated benzene phase was distilled at 20 mm. pressure. The oily residue was dissolved in 50 ml. anhydrous ether and the resulting solution was treated with 50 ml. ligroin and cooled to 0C, whereby 7.5 g. 3-(4,5-diphenyl-2-oxazolyl)-propionic acid N,N-diethylamide crystallized, m.p. 6l63C (yield 54 In the following Table the compounds of the formula (I) prepared as described in the preceding Examples and other compounds which can be obtained with simi- .lar procedures are listed together with the respective melting points.

6 TABLE I) 4,5-diphenyl-2-oxazolyl-carm.p. l50l52"C boxylic acid N-methylamide 2) 4,5-diphenyl-2-oxazol l-carm.p. l30132C boxylic acid N,N-diet lamide 3) 4,5-diphenyl-2-oxazoly -carm.p. l5B-l59C boxylic acid pyrrolidide 4) 4,5-diphenyl-2-oxazolyl-carm.p. l4l-l42"C boxylic acid morpholide 5) 4,S diphenyl2-oxaz Iyl-carboxym.p. ll92C lic acid N',N'-dimethylhydrazide 6) 4,S-diphenyl-oxazolylacetic acid m.p. l39l42C N-melhylamide 7) 4,5- Iwhonyl-2-oxazolylacetic m.p. S9-6l"C acid ,N-diethylamide 8) 4,5-diphcnyl-Z-oxazolylacetic m.p. l29l3lC acid pyrrolidide 9) 4,S-diphenyl-2-oxazolylacetic m.p. l27-l29C acid morpholide l0) 4,5-diphenyl-Z-oxazolylacetic m.p. l64l65C acid hydrazide ll) 3-(4,5-diphcnyl-2-oxazolyl)prom.p. l28-l30C ionic acid N-methylamide l2) -(4,S-diphenyl-2-oxazolyl)-pro mp 6l63C ionic acid N,N-diethylamide l3) -(4,5-diphenyl-2-oxazolyl)prom.p. (if-66C pionic acid pyrrolidide l4) 3-(4,5-diphenyl-2-oxazolyl)prom.p. l01-l03C pionic acid morpholide l5) 3-(4,5-diphenyl-2-oxazolyl)-prom.p. l27l29C pionic acid hydrazidc l6) 3-(4,5-diphenyl-2-oxazolyl)-prom.p. l37l39C pionic acid N, N'-dimcthylhydrazide I claim: 1. 4,5-Diphenyl-2-oxazolyl-carboxyllc and N- methylamide.

2. 4,5-Dlphenyl-2-oxazolyl-carboxyl1c acid, N,N-d|ethylamide.

3. 4,5-Diphenyl-Z-oxazolyl-carboxylic acid N',N- dimethylhydrazide.

4. 4,5-Diphenyl-Z-oxazolylacetic acid hydrazide.

5. 3-(4,5-Diphenyl-2-oxazolyl)-propionic acid hydrazide.

6. 3-(4,5-Diphenyl-2-oxazolyl)-propionic acid N,- N'dimethylhydrazide. 

1. 4,5-DIPHENYL-2-OXAZOLYL-CARBOXYLIC ACID N-METHYLAMIDE.
 2. 4,5-Diphenyl-2-oxazolyl-carboxylic acid, N,N-diethylamide.
 3. 4,5-Diphenyl-2-oxazolyl-carboxylic acid N'',N''-dimethylhydrazide.
 4. 4,5-Diphenyl-2-oxazolylacetic acid hydrazide.
 5. 3-(4,5-Diphenyl-2-oxazolyl)-propionic acid hydrazide.
 6. 3-(4,5-Diphenyl-2-oxazolyl)-propionic acid N'', N''dimethylhydrazide. 